In modern day turbomachines various components of the turbomachine operate at very high temperatures. These components include the blade or vane component, which are in shape of an airfoil. In the present application, only “blade”, but the specifications can be transferred to a vane. The high temperatures during operation of the turbomachine may damage the blade component, hence cooling of the blade component is important. Cooling of these components is generally achieved by passing a cooling fluid that may include air from a compressor of the turbomachine through a core passage way cast into the blade component.
The blade typically includes an airfoil portion and a root portion separated by a platform. The airfoil portion of the blade is cooled by directing a cooling fluid to flow through radial passages formed in the airfoil portion of the blades. Typically, a number of small axial passages are formed inside the blade airfoils that connect with one or more of the radial passages so that cooling air is directed over the surfaces of the airfoils, such as the leading and trailing edges or the suction and pressure surfaces. After the cooling air exits the blade it enters and mixes with the hot gas flowing through the turbine section.
Typically, cooling of the blade is achieved by supplying the cooling fluid from the compressor to the cooling channels in the blades. The cooling channels often include multiple flow paths that are designed to maintain all aspects of the turbine blade at a relatively uniform temperature.
Several different cooling arrangements based on a combination of convective, impingement, and external film-based cooling have been proposed in the state of the art.
Some of the existing designs of the blade require too much amount of cooling fluid to pass through the channels and cavities therein, to provide a desired cooling to the blade.